Republican presidential hopefuls attempted to one-up each other on war and torture during Saturday night’s New Hampshire debate, with frontrunner Donald Trump promising to “bring back a hell of a lot worse than waterboarding.”

Asked by debate moderator David Muir whether they would embrace the interrupted drowning technique known as waterboarding for use on Islamic State militants and other terrorism suspects, the three leading GOP candidates—Trump, Sen. Ted Cruz (R-TX) and Sen. Marco Rubio (R-FL)—and former Florida governor Jeb Bush all answered affirmatively.

Not to be outdone, Trump went a step further. “In the Middle East, we have people chopping the heads off Christians. We have people chopping the heads off many other people,” he said. “Not since medieval times have people seen what’s [now] going on. I would bring back waterboarding, and I’d bring back a hell of a lot worse than waterboarding.”

Pressed on his endorsement of illegal torture, Trump told CNN on Sunday that he would seek to alter the law so that waterboarding is no longer classified as a war crime.

“I’d go through a process and get it declassified, frankly… certainly waterboarding at a minimum,” Trump told CNN’s Jake Tapper on “State of the Union.” Trump did not say what he would authorize that is “a hell of a lot worse than waterboarding.”

Cruz, while saying he “would not bring it back in any sort of widespread use,” refused to acknowledge that waterboarding is torture, citing an illegal Bush-era redefinition of torture as abuse that causes “excruciating pain that is equivalent to losing… organs and systems” to justify his stance.

“So, under the definition of torture, [waterboarding] is not,” asserted Cruz. “It is enhanced interrogation, it is vigorous interrogation, but it does not meet the generally recognized definition of torture.”

However, under domestic and international law, waterboarding is undeniably torture and the technique has been prosecuted as a war crime for generations. A favorite torment of tyrannical regimes from the Spanish Inquisition to the Nazis to the Khmer Rouge, Japanese soldiers were tried, convicted and executed for waterboarding American POWs during World War II. Americans were punished for waterboarding prisoners during the Philippine-American and Vietnam wars and even many Republicans—including torture victim Sen. John McCain (R-AZ)—have condemned the technique as brutal torture.

“Anyone who knows what waterboarding is could not be unsure,” insisted McCain. “It is a horrible torture technique… and should never be condoned in the US… We are a better nation than that.”

Americans who have been waterboarded also emphatically concur that it is torture.

“I felt more or less like I was drowning, just gasping between life and death,” recalled Lt. Chase J. Nielsen, a US airman captured by the Japanese during World War II.

President Barack Obama signed an executive order banning waterboarding and other torture techniques almost immediately after taking office in 2009, a move that was harshly criticized by many Republicans who claimed the president was stripping away a valuable tool in the fight against terrorism. However, most experienced interrogators emphatically assert that information obtained through torture is unreliable at best.

“Let me be clear on one crucial point: it is the terrorists whom we won over with humane methods… who continue to provide the most reliable intelligence we have in the fight against al-Qaeda,” wrote Jack Cloonan, a 25-year FBI veteran formerly assigned to the bureau’s Osama bin Laden unit, “and it is the testimony of terrorists we tortured after 9/11 who have provided the most unreliable information, such as stories about a close connection between al-Qaeda and Saddam Hussein.”

The US Senate’s damning December 2014 report on the Central Intelligence Agency’s torture of terrorism suspects concluded that contrary to claims by top Bush officials, the CIA ‘enhanced interrogation’ program was ineffective at producing terror-thwarting intelligence, and that at no time did torture lead to any information about an imminent terror threat. However, CIA Director John Brennan released a statement in the wake of the Senate report’s release defending the agency’s torture program, claiming it “did produce intelligence that helped… save lives.”

Approved ‘enhanced interrogation’ methods included waterboarding, sleep, sensory and food deprivation, shackling in excruciating ‘stress positions,’ the use of loud music and dogs to torment detainees, slamming into walls, solitary confinement, exposure to extreme heat or cold and sexual humiliation.

In addition to these approved techniques, US military and intelligence personnel subjected terrorism detainees—many of them innocent men, women and children—to additional abuses, including homicide, rape, imprisonment of relatives as bargaining chips, exposure to sometimes lethally extreme temperatures and brutal beatings.